TROUBLE  PROBABLE CAUSE  ISOLATION PROCEDURE  REMEDY 
Excessive pedal forces  NOTE: If excessive force is only in certain portions of rudder pedal travel, probable cause is interference in system or binding due to defective or worn parts. If excessive force is through the entire travel range, probable cause is in the artificial feel system or high system friction due to worn parts Foreign objects interfering with system components and linkages Binding worn or defective parts in rudder pedals or forward quadrant and jackshaft installation, structural interference in area of rudder pedals  Check for foreign objects obstructing movement of system components and linkages Disconnect RA and RM cables from forward quadrants. Cycle pedals through maximum travel and check for resistance. If binding or resistance is encountered, defective part is in rudder pedal linkage or forward quadrant and jackshaft assembly, or structure in area of rudder pedals  Remove foreign objects Repair or replace defective parts 

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BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 

TROUBLE  PROBABLE CAUSE  ISOLATION PROCEDURE  REMEDY 
Excessive  Binding worn or  Remove RA and RB cables  Repair or replace 
pedal forces  defective parts in  from aft quadrant. Disconnect  defective parts 
(Cont)  rudder aft control quadrant torque tube or feel and centering unit Binding in power control unit valve input rods or power control units Excessive system friction Defective centering unit  linkages connecting torque tube to rudder aft control quadrant, feel and centering unit, power control unit and standby actuator. Disconnect feel and centering unit output crank from feel rod connection. Rotate feel and entering unit, aft quadrant, and torque tube to check for interference With rudder power control unit and standby actuator input rods disconnected from torque tube, cycle input rods by hand to check for binding input linkages Test rudder centering per 27-21-0, Rudder and Rudder Trim Control System -Adjustment Test. If rudder does not return to neutral, system friction may be excessive. Refer to Faulty Rudder Centering Trouble Shooting Replace centering unit and recheck forces  Replace defective power control unit Repair or replace defective part 

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TROUBLE  PROBABLE CAUSE  ISOLATION PROCEDURE  REMEDY 
Rudder pedal forces low Excessive play in pedals  Defective centering unit Worn or defective parts in rudder pedals or forward quadrant and jackshaft area  Replace centering unit and recheck forces Clamp forward quadrant to structure to prevent motion of quadrant. Check rudder pedals for excessive play  Repair or replace defective part Repair or replace defective parts 

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TROUBLE  PROBABLE CAUSE  ISOLATION PROCEDURE  REMEDY 
Excessive play in pedals (Cont) Rudder pedal jams or binds when brakes are applied Insufficient pedal adjustment travel Excessive pedal adjustment forces Pedal adjustment binds in full forward or full aft position Rudder pedal adjustment moves Insufficient trim knob travel or rudder trim travel  Worn or defective parts in rudder aft quadrant, torque tube or feel and centering unit area Pedal interferes with pedal mechanism cover Foreign objects or defective parts in jackshaft assembly Foreign objects or defective parts in jackshaft assembly Defective or binding flexible shaft Jackshaft overrotated in adjustment nut Loose, worn or defective parts in jackshaft assembly Foreign objects or structure interfering with rudder trim actuator or centering unit  Determine if excessive play occurs with power on but normal with power off. If it does, problem is in centering unit or input linkage to it. If it is determined problem is not in the fwd quadrant area or centering unit, problem is in the linkage between the aft quadrant and torque tube Check clearance between pedals and cover thru full travel range with brakes applied Check for defective parts or foreign objects in jackshaft assembly Check for defective parts or foreign objects in jackshaft assembly Remove flexible shaft, determine if defective Check that rudder pedals are adjusted fully forward or fully aft Check jackshaft assembly for loose, worn or defective parts Check for foreign objects or interference in area of rudder trim actuator and centering unit  Repair or replace defective parts Remove interference Remove foreign object, replace or repair defective parts Remove foreign object, replace or repair defective partsReplace defective flexible shaft Backdrive rudder pedal adjustment crank up to 100 pound-inches torque to free the bound mechanism Repair or replace defective parts Remove foreign object or interference 
　
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